Emergency-brake control



Sept. 1, 1925.

E. B. MEAD EMERGENCY BRAKE CONTROL 3 Sheets-Sheet 1 Filed July 30, 1921 wW W wmm Sept. 1, 1925. 1,551,830

E. B. MEAD EMERGENCY BRAKE CONTROL Filed my 30. 1921 s Sheets-Sheet 2 Sept. 1, 1925. v

, "E. B. MEAD EMERGENCY BRAKE CONTROL FiledJuly so, 1921 s Sheets-Sheet 5 Patented Sept. 1, 1925. V i

UNITED STATES 1,551,830 PATENT OFFICE.

EZRA B. MEAD, OF OTTUMWA, IQWA, ASSIGNOR TO CTTUMWA IRON WORKS, OF

OT'IUMWA, IOWA, A CORPORATION OF IOWA. 1

EMERGENCY-BRAKE CONTROL.

Application filed July 30, 1921. Serial No. 488,561.

To all whom it may concern:

Be it known that LEZRA B. MEAD, a citizen of the United States, residing in Ottumwa, in the county of VVapello and State 5 of Iowa, have invented a new and useful Improvement in Emergency-Brake Controls, of which the following is a specification.-

This invention relates in general to hoisting apparatus and has more particular reference to the brake control providedfor use in drum hoists which are employed for, moving trains of cars on a slope, thoughit should be observed that it is not limited to any particular type of hoisting device and may be of general application in hoisting and elevating machinery.

In hoists such as are employed in the mines and elsewhere it is usually the custion of the brake under certain predetermined conditions, as for example, when the power, falls, excessive 'speed 18 attained,

and the like. These controls work admir at a speed faster than the gravity retarda tion of the upwardly moving train the rope slackens and when the train is finally brought to rest it may then have a free fall or free run taking up the slack thus provided. This action, of course, has a tendency and has been known to break the cable scend.

It is a principal object ofniy invention to provide means for controlling the emergencyapplication of the brake so that the drum will not be slowed in: excess of the gravityretardation of the upwardly moving load. In the present instance the apparatus embodying the invention is adapted, if desired, to place a light braking action by the hoist brake during the remaining up movement or preferably to delay the action of the hoistbrake until the hoist is brought to tom to provide for the emergency applica-' permitting the train to violently dew I 7 application. 7 The brake itself is not shown rest by gravity and then immediately apply it before the hoist has opportunity to move downwardly an appreciable distance.

Another important object of my invention is the provisionof apparatus of this character, which need not interfere in any particular with the manual control of the hoist brake and which, need not require reconstruction of the brake control, the emergency mechanism or the devices controlling it.

Another highly important object of my invention is the provision of an apparatus accomplishing the aforesaid general purpose, which in service will have no moving parts except when actually in operation and which on this and other accounts will not require frequent repair, replacement or readgustment.

Numerous other obgects and advantages of I the invention will be apparent as it is better understood from the following description,

which, taken in connection with the acco1npanying drawings, discloses a preferred embodiment thereof.

Referring to the drawings,

Fig. 1 is a side elevation of the controller for operation of the brake control mechanism of the character described; Fig. '2 is a side elevation of the brake deferring or delaying portion of the apparatus; i

Fig. 3 is Fig. 2;

Fig. 4 is a section taken substantially on the'line ti of Fig. 2; and

Fig.- 5 is a section taken substantially on the line 55 of Fig; 2.

For the purpose of illustrating my invention I have shown on the drawing in Fig. 1' a side view of a brake cont-roller mechanism in which isprovided an arrangement for both manual and emergency hoist brake a View looking from the right in oirtlie drawing since it may be of any wellknown or preferred construction and is fluid actuated, compressed air, oil or water being employed. Brakes ofthis' character are usually and desirably applied through the agencyof powerful; weights or springs,

lid

ed the necessary valve parts to cause fluid under brake releasing pressure to pass to the brake cylinder in the known fashion. This valve is preferably of the character of that described in U. S. Letters Patent No. 1,373,196 issued to the Ottumwa Iron orks as my assignee on March 29, 1921. The brake control shown in Fig.1 in many respects is like that of this patent. It comprises an operating'shaft 12 mounted in a suit-able bearing construction 13 and carrying a loosely mounted brake lever 14 of bell crank construction. The valve control arm 15 of this lever 14 is angled at 16 and again at 17. The valve casing is supported in supports 18 from the bearing construction 13 and its valve stem 19 is attached to a plate 21 in turn attached at 22 to a floating lever 28. This lever extends at one end (the right) heneath the arm 15 of the manually controlled lever 1e andis attached at its other end at 2x to a lever 25 keyed on the shaft 12 at 26. The lever 25 engages under a latch 27 of an emergency control, this latch being mounted in the bearing 28 and having a weight 29 pulling it over into engaging position.

The pressure of the fluid inthe brake control system is applied beneath the valve as is indicated in my prior patent above-mentioned, this pressure when conditions permit tending to raise the valve and permit release of the brake applying devices at the brake.

,A counter weight 31 is pivoted upon a bar 32 connected by links 83 with the plate 21,

" this counter weight, however, being less than the pressure within the valve. An arm 34; is also keyed upon the shaft 12 and from this arln a weight 35 is suspended by a rod 36. Set screws 37 and 39 are provided in the arm 15 of the manuallycontrolled lever to produce operation of the float lever 22). Then it is desired to apply the brakes the. lever is moved in a counter-clockwise direction, viewing the figure, and the valve:

opened to exhaust from the brake operating cylinder'and this pressure may be restored to release the brakes by movement in. the opposite direction. ,l Vhen emergency conditions, requiring application of brake, occur the trip 27 is moved over electromagnetically or otherwise permitting release of the lever 25, thus freeing the valve from restraining action and permitting it to rise. In this connection the weight 35 is opposed. to the weight 31 and emergency brake application may result. So much of the appara tus as has just been described is of the general type shown in my prior patent above referred to and more particular showing and description is not, therefore, thought necessary.

In order to prevent movement of the brakes in emergency action during ascension I provide a device or apparatus which will now be described and it may be considered as a separate attachment or as a part of the general brake control. Referring to Fig. 2, reference character 51 indicates the drum shaft or similar part moving in accordance with the drum either at like or at proportional speed. This shaft is mounted in suitable hearing at In the present instance I arrange the device about the shaft providing an. embracing band or member 53 very much like ahand brake. This band at the lower end is attached at to a member which is connected by a link 06 with a pin 57 in an upright link 58. The other end. of the band is pivoted at 59 in a lever 61 pivoted at one end at 57 in the link 58 and at the other at 62 to the upper end of a rod 63. The link 58 is pivoted respectively at 6% and 65 to links 66 and 67, these links being pivoted in turn at 68 and G9 in the main frame of the machine ant preferably vertically beneath the center of the shaft 51. The link 67 is provided at its opposite end with a weight 71 and has a downwardly extending bracket construction 72 in which is pivoted the tail 7 3 of a second weight 7 1. The tail 73 has a stop 75 for engagement with the other side of the link 67 and the weight 7 1 has a stop 76 adapted for engage ment with the pin 77 in the frame, the purpose of which will be presently more fully described.

The rod 63 is connected at 78 with one arm 79 of a bell crank lever pivoted at 81 to the frame,-the. other arm 82 of this bell crank is connected at 83 with a link on rod 84 engaged at with an arm 85 also connected on the operating shaft 12 of the brake control mechanism. The arm 85 is keyed on the operating shaft so that it moves with any movement of the lever 25.

hen the trip is released during tie upmoven'ient of the train, the trip lever 25 tends to move up tightening the band 53. This causes the band to tend to rotate with the drum shaft 51. This results in a downward swinging movement of the weight 71 and an upward swinging movement of the weight 7 4- about the stop 77, these two weights soon coming to rest by engagement with each other and permitting the shaft 51 to slip This movement permits a slight compensation for the movement of the trip lever and no en'iergency application of the brake has resulted. hen the shaft 51 comes to rest it iniinediatcly starts in the reverse direction under the gravity action of the train. This causes the band 53, which is still tightly about the shaft, to tend to move in the opposite direction and the two weights may be swung about the pivot points (59, the link 5b thus moved downwardly and en'iergency brake application results.

Attention is directed to the angularity of the bell crank consisting of the arms 79 and 82 and also its angular relation with respect to the rods 63 and 84. This arrangement produces minimum motion of the trip lever 25'for a given movement of the little lever 61.

The band 53 in the normal running of the apparatus is out of contact with the shaft,.

the parts being overbalanced by the weights 71 and 7a. A support 86 is provided for the band. It is to be noted that during thisnormal. operation, none of the brake parts are in motion or in contact with parts which are in motion, so that no vopportunity'for wear at such times is provided;

The parts may be so set and arranged that the little lever 61 will not wholly compen sate for the tripping movement with slight braking action resulting on the lip-stroke. All that is required in this respect is a sufficient movement of the parts to permit the valve to open slightly'as will be readily understood.

The shaft 51, when the drum is hoisting, rotates in counter-clockwise direction, as indicated by the arrow in Fig. 2. As previously stated, the band 53 is not affected by normal rotation of said shaft and is only brought into contact therewith when the trip lever 25 is actuated. In this event, it moves with the shaft until stopped by the action of the weights 71 and Tet, the shaft then slipping within the band until brought to rest. Upon reversal of direction of rotation of the shaft 51and band 53, the latter is loosened andthe'lever 25. may be moved sufiiciently to permit the emergency brake to be applied.

It is thought that the invention and many of its attendant advantages will be understood from the foregoing description, and it will be apparentthat various changes may be made in the form, construction and arrangement of the parts without departing from the spirit and'scopeof the invention or sacrificing all of its material advantages the form hereinbefore described being merely a preferred embodiment thereof.

I claim:

1. In a hoisting apparatus including a hoist mechanism and a brake therefor, the combination of an emergency control, for said brake, and means for preventing braking action under the emerge'ncy control in advance of gravity retardation while the hoist is lifting, said means comprising a member rotatable with the hoist and means actuated by contact with said'meinber for delaying the application of the brakes. l"

.2. In a hoisting apparatus including a hoist mechanism and a brake therefor, the combination of an emergency control for said brake, and means for delaying braking action under the action of said emergency 7 control while the hoist is lifting, said means said member fordelaying the application of the brakes.

3. In a hoisting apparatus, provided with a hoist drumand a brake, the combination of a member moving in accordance with said drum, means for applying said brake, an emergency release for said means,'and a device engaging said member to prevent actuation of the brake while the member is moving in accordancewith the up movement of the drum.

a. In a hoisting apparatus, provided with a hoist drum and a brake, the combination of a member moving in accordance with said drum, means for applying said brake, an emergency release for said means, and a device moved into engagement with said member by the initial action of said release for preventing brake application during the up movement of the drum.

5. In a hoisting apparatus, provided with a hoist drum and a brake, the combination of a member moving in accordance with said drum, means for applying said brake, an emergency release for said means, and a device movable into engagement with and actuated by said member to facilitate the action of-saidrelease during the down movement of the drum.

6. Ina hoisting apparatus, provided with a hoist drum and a brake, the combination of a member moving in accordance with said drum, means for applying said brake, an emergency release for said means, and a device movable on the operation of said release into engagement with said member during the up movement of the drum to prevent action of said brake applying means during the up movement of the drum and permitting release of said brake applying means during the down movement of the drum;

7. In a hoisting apparatus, provided with a hoist drum and a brake, the combination of a member moving in accordance with said drum, means for applying said brake, an emergency release for said'means, and a device movable on the operation of said release into engagement with saidmember during the up movement of the drum to prevent action of said brake applying means during the up movement of the drum, and permitting application of said'brake applying means as soon as the drum starts its downward movement. I

8. In a hoisting apparatus, provided with a hoist drum and a brak'e, the combination of a member moving in accordance with said drum, means for applying said brake, an emergency release for said means, and a device embracing said member and adapted to be tightened thereaboutby the initial action of said release for controlling its releasing action to prevent brake application during the up movement.

9. In a hoisting apparatus, provided with a hoist drum and a brake, the combination of a member moving in accordance with said drum, means for applying said brake, an emergency release for said means, and a device embracing said member and adapted to be tightened thereabout by the initial action of said release, said device being' movable against the releasing action in one direction to prevent brake application and with the releasing action in the opposite direction of drum movement to permit brake application.

10. In a hoisting apparatus, provided with a hoist drum and a brake, the combination of a member moving in accordance with said drum, means for applying said brake, an emergency release for said means, and a device embracing said member and adapted to be tightened thereabout by the initial action 01 said release, said device having a slipping engagement with said member during the up movement of the drum to prevent brake application.

11. In a hoisting apparatus, provided with a hoist drum and a brake, the combination of a member moving in accordance with said drunr, means for applying said brake, an

emergency release for said means, and a device embracing said member and adapted to be tightened thereaboutby the initial action of said release, said device being held against substantial movement with said member in the up movement of the drum to prevent brake application.

12. In a hoisting apparatus, a drum shaft, means for applying a brake to said drum shaft, means for releasing said brake applying means, an emergency control for said releasing means, and a device embracing said drum shaft, said device being movable into engagement with said shaft in the initial movement of the emergency control, rotation of said shaft in the up movement of the drum delaying the en'iergency control action.

131' In a hoisting apparatus, a drum shaft, means for applying a brake to said drum sha-t't, means for releasing said bralre applying means, an emergency control for said releasing means, and a device embracing said drum shaft, said device being movable into engagement with said shaft in the ini tial m vement of the emergency control, rotation of said shaft in the up movement of the drum delaying the emergency control action until the down movement of the drum occurs.

14. In a hoisting apparatus, a drum shaft, means for applying a brake to said drum shaft, means for releasing said brake applying means, an emergency control for said releasing means, and a device embracing said drum shaft, said emergency control including a trip releasing said control under certain predetermined conditions, and said device embracing the drum shaftbeing moved into engagement therewith on release or the trip for preventing actuation of said emergency control during the up movement of the drum and until it starts its down movement.

EZRA B. MEAD. 

